Suggestions for Priest T13 set bonuses?

What are your guys' ideas for the set bonuses coming along with the new T13 gear? I have to say the current T12 is pretty damn nice. Mine:

Your Prayer of Mending has a 2% chance to apply a Renew on its target.

or

Casting Prayer of Mending causes you to gain a stack of a buff. When this buff reaches 3 stacks, the next Circle of Healing or Power Word: Shield is taken off the Global Cooldown.

Buff resets when used. Maybe a different spell in favor of Disc. Perhaps taking the next Prayer of Mending off GCD. I dont know the math enough to determine if these would be balanced or too OP in any way.

Healing Set:
2 set: An HPS booster (ex/ Greater Heal adds an absorb for 20% of its healing)
4 set: A mana booster (casts have a chance to proc x% mana with a small ICD or some such)

Shadow Set:
2 set: A DPS booster (ex/ SWP has a 25% chance to proc an additional tick's worth of dmg)
4 set: A DPS/mana booster (Your shadowfiend becomes a permanent guardian in reduced strength, ie 1/3 of its DPS and 1/4 of its mana returns per hit)

With the above set bonuses, no funny business with 2set tier 12 + 2set tier 13 is going on, and in both cases it should be worth breaking 4 set tier 12 if you have factor in the boost to stats as well.

What I'd like to see;
Healing
2set: you gain x amount of haste after casting PoH for x seconds.
4set: reduces the mana cost of AoE healing spells by x%.

Set bonuses like that scare me, as it tends to pigeon-hole us into a raid-healing role. There are already enough ill-informed people out there that say that "Discipline is for Tank-healing only" and "Holy is for Raid-healing only"; we don't need another group of people saying that "Priests are for Raid-healing only, period."

I'd prefer something along the lines of...

2-set: Your Penance, Attonement, Heal, Flash Heal, and Greater Heal have a chance to reset the cooldown of your Inner Focus.
4-set: Increases the Priest's casting Speed by 50% for 8 seconds when starting to channel any Hymn. OR Doubles the number of targets that the Priest's Hymns affect.

Basically, going with the paradigm of one "regen" bonus and one "throughput" bonus (that could also be used for regen). The 2-set's proc chance would have to be controlled (and probably not absurdly high) to keep it from being imbalanced. I'm not *super* in love with either of the 4-set bonuses, but, I think the casting speed one would be interesting. If you channeled a full Hymn, you'd be getting 1.5x the number of ticks, OR if you started the Hymn and immediately canceled, you'd get 8 seconds of (mostly) GCD-capped casting. Because of the long CD of both Hymns, most fights would only allow you to benefit from this a couple times (longer fights would, obviously, see more usages). The Casting Speed % could also, obviously, be tweaked.

shadow
2-set : your mindblast / sw:death adds 3/6 seconds to the duration of vt / the other dot i can't remember the name
4-set : your dot ticks have a 5% chance to empower you with the dark powers of someone , the damage of your next mindblast is doubeld

2pc: Your Echo of Light transforms into Serenades of Light. Serenades of light bathes your target in a wall of light that absorbs twice the amount healed from your direct healing spells, as well as applying the old HoT.
Your Shield Mastery transforms into Bastion of Light. Every shield you place on the target multiplies the shield by 2 and turns it into a HoT for 5 seconds. The effect does not stack, as well as keeping the old bonus to shields.
It'd be a way to make segregate the roles of tank healer/raid healer for both specs.
4pc: Your Chakra turns into Nirvana: You gain the Spirit of Redemption model, all healing is increased by 20%, you get a battle rez, however you're stuck in place, and chakra now has a CD, due to it's elevated state.
Your Power Word Barrier now applies a Power word shield over all members in your raid/party, as well as dropping a barrier in your targeted location. Also increases the absorbtion amount of both by 15%, however mana cost is increased by 35%.

Shadow:
2pc: Your Shadow Orbs become Spheres of Utter Darkness. They act like the old Shadow Orbs, but once you hit 5, they add an additional affect to the following:
Mind blast applies a DoT to the target
Mind Spike acts as if 2 were cast, instead of one
3 Miniature Shadow Fiends spawn along with your major one, however the big one only returns mana
Dispersion now allows you to fade into the shadows to regain mana, however you can still cast, move and your spells become 10% stronger, do to you being able to be immersed in pure shadow energy
Fade removes all threat instantly
4pc: Your mind sear now applies Shadow word Pain on all targets hit
Your Devouring Plague can now hit 5 targets

Shadow:
2set: Chance of getting an orb thourgh Mind Flay/SWP is increased by 5% / 10% also you can gain up to a 1 orb per 1 Mind Sear Cast
4set: While shadow fiend is up your shadow spells are 5% / 10% stronger

Healing:
2 piece: Shadowfiend now also heals the lowest health target within 20 yards by 5% of their total health when it attacks
4 piece: Reduces the cooldown of Divine Hymn and Hymn of hope by 50%

2 piece opens up new posibilites for shadowfiend useage other than just to regen mana or to do some extra damage.
4 piece would mean you could use both these cooldowns twice each fight. Wouldn't be too OP imo, as almost every other cooldown nowadays are 3 minutes or less. T13 will also likely be the last tier of the expansion, meaning the bonus won't be too good to replace with a later tier.